1. Field of the Invention
The present invention relates to an optical non-contact laser straight ruler and a method for measuring a distance and projecting a line using the laser straight ruler, and more particularly, to an optical non-contact laser straight ruler which can measure the distance of an object in three dimensions and reproduce the distance of the object, and a method for measuring a distance and projecting a line using the laser straight ruler.
2. Description of the Related Art
In general, a measuring tape or bar ruler which is used to measure a distance or draw a line in a contact manner is inconvenient to carry and difficult to measure the distance such as height or width of an object placed at a position that one cannot easily access. To address the problem, a straight ruler which can measure a distance optically in a non-contact manner is needed.
FIG. 1 shows a conventional non-contact type measuring device which is disclosed in U.S. Pat. No. 4,494,874. Referring to FIG. 1, the conventional non-contact type measuring device measures an object in a triangulation method and includes a projector 3, a camera 5, and a control portion 7. The projector 3 projects a laser spot SL that is movable onto an object 1 to be measured. The camera 5 photographs the laser spot SL illuminated onto the object 1 to measure the light intensity and position of the laser spot SL. The control portion 7 receives a signal proportional to the intensity of light received by the camera 5 and adjusts the amount of light projected by the projector 3.
Thus, the object 1 is scanned by flying the laser spot SL illuminated onto the object 1 so that three dimensional information of the object 1 can be obtained in a triangulation method from a signal measured in synchronization with the scanning. In the meantime, since the use of the conventional non-contact measuring device is restricted to the obtainment of the three dimensional information of the object 1, the application field of the device is limited.